Reply by ferstler

The Ridgid 0610 (I own one, too, and have a review of it somewhere on this site) does fine as a single-surface planer with stock no more than six inches wide, but it will not parallel opposing sides. To do that you need a thickness planer, such as the Ryobi 1300 that I use (I have reviewed this tool on this site, somewhere, too).

Both tools complement each other, although as Scott says, with a bit of inginuity one can use a thickness planer as a flattener.